Comparison of Giemsa microscopy with nested PCR for the diagnosis of malaria in North Gondar, north-west Ethiopia

Malaria Journal

Research

Afework Kassu¹  Sisay Getie²  Gebeyaw Getnet²  Abebe Alemu²  Hans-Peter Fuehrer³  Harald Noedl⁴ 

[1] Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia;Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia;Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria;Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria;

关键词: Malaria;    Plasmodium;    Mixed Infection;    Nest Polymerase Chain Reaction;    Malaria Diagnosis;   

DOI  :  10.1186/1475-2875-13-174

 received in 2014-02-16, accepted in 2014-05-02,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundMalaria remains one of the leading communicable diseases in Ethiopia. Early diagnosis combined with prompt treatment is one of the main strategies for malaria prevention and control. Despite its limitation, Giemsa microscopy is still considered to be the gold standard for malaria diagnosis. This study aimed to compare the performance of Giemsa microscopy with nested polymerase chain reaction (nPCR) for the diagnosis of malaria in north-west Ethiopia.MethodsA cross sectional study was conducted in public health facilities in North Gondar, from March 2013 to April 2013. A total number of 297 subjects with suspected malaria were enrolled in the study. Finger-prick blood samples were collected and examined for Plasmodium parasites using Giemsa microscopy and standard nPCR.ResultsAmong the study participants, 61.6% (183/297) patients tested positive for malaria by Giemsa microscopy of which, 72.1% (132/183) and 27.9% (51/183) were diagnosed as Plasmodium falciparum and Plasmodium vivax, respectively. By nPCR, 73.1% (217/297) were malaria-positive. Among microscopy-negative samples, 13.1% (39/297) samples turned malaria-positive in nPCR. In nPCR, the rate of mixed Plasmodium infections was 4.7% (14/297) and 3.03% (9/297) were positive for Plasmodium ovale. Using nPCR as reference the sensitivity, specificity, positive predictive and negative predictive values of Giemsa microscopy were 82.0%, 93.8%, 97.3% and 65.8%, respectively, with a good agreement (κ = 0.668) to nested PCR. The sensitivity and specificity of Giemsa microscopy in identifyingP. falciparium infections were 74.0% and 87.4% and 63.2% and 96.5% for P. vivax infections, respectively.ConclusionAlthough Giemsa microscopy remains the gold standard for malaria diagnosis in resource-limited environments, its sensitivity and specificity as compared to nPCR is limited suggesting exploration of novel rapid and simplified molecular techniques for malaria-endemic countries. A high rate of misclassification and misidentification highlights the importance of adequate training for staff involved in malaria diagnosis.

【 授权许可】

Unknown   
© Alemu et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.